This post is based on ES3. Both U+2028 and U+2029 are valid in ES5 string literals as part of a LineContinuation. See http://es5.github.com/#x7.3 (ES5) instead of http://bclary.com/2004/11/07/#a-7.3 (ES3).

So really, the title should be: “JSON: The ES3 subset that isn’t.”

Issue reported: https://github.com/judofyr/timeless/issues/57